Yes, I do the opposite of what you want on my laptop. I receive the wireless signal and use the laptop to serve my vonage phone through the nic card.
I'm not sure if your wifi card can be used to serve but at the least the two connections will have to be in bridge mode.

Go to your network connections in control panel and select both cards ( draw a box with left click drag), right click on them and select bridge connections.
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You may find you actually need a router to do what you're asking it to do, I'm not sure if you can get your card to broadcast . I'm guessing it's going to be hardware dependant.

In the Network and Sharing Center, you should have the option to Create a Network Connection or something along those lines. In there should be a choice to make an Ad-Hoc Wireless Network, just follow through the wizard and at the end it should ask if you want to enable Internet Sharing, do so and I think you'll have what you want.

EDIT: After re-reading again, sounds like the computer with Internet is running XP so I guess the above won't apply. I haven't used XP in ages so I don't know.